Die for making bit-stock tools



APPLICATION FILED JUN; 16,6919.

Patented Jan. 25,1921

2 SHEETS-SHEET 1 E. T. McPHERSON.

DIE FOR MAKING an STOCK TOOLS.

APPLIGATION FILED JUNE 16, I919- 1,366,816." PM Jan 5,1921.

2 SHEETS SHEET 2.

UNITED STATES PATENT OFFECE.

DIE FOR MAKING BIT-STOCK TOOLS.

Application filed June 16, 1919.

To all whom it may concern Be it known that l, ELMEB. T. MoPr-rnnsoN, a citizen of the United States, residing at Wallingford, in the county of New Haven and State of Connecticut, have invented new and useful Improvements in Dies for Male ing Bit-Stock Tools; and I do hereby declare the following, when taken in connection with the accompanying drawings and the characters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this application, and represent, in-

Figure 1 a plan view of lower die embodying my invention.

Fig. 2 an end view thereof.

Fig. 3 a plan view of the complementary upper die.

Fig. t an end view thereof.

Fig. 5 an end view showing the two dies closed together, with a blank between them.

Fig. 6 a front view of the two dies as closed together.

Fig. '7 a broken perspective view of such a blank as may be subjected to the action of my improved dies.

Fig. 8 a corresponding view of the blank as it appears after the first operation.

Fig. 9 a view of the blank as it appears after the second operation.

Fig. 10 aview of the blank at the conclusion of the third operation by which the bit-stock is completed except for marking it.

Fig. 11 a. corresponding view showing the bit-stock as marked.

My invention relates to'an improvement in the dies used in the production of auger bits, expansion bits, drills, reamers, screw drivers, and other kindred tools designed to be used in bit-stocks, the object being to simplify and cheapen tools of this character as well to produce them with a degree of finish and uniformity not before attained.

With these ends in view, my invention consists in dies having certain details of construction asv will be hereinafter described and pointed out in the claims.

In carrying out my invention as herein shown, I employ a lower .die 2 and an upper die 3, designed to be installed in a triphaminer of any approved form. The lower die is provided at its left'hand front corner with .a flat forging-surface r the rear edge of which merges into a rearwardly inclined clearance-surface 5 of the same area, the upper die having complementary surfaces 6 Specification of Letters Patent.

Patented Jan. 25, 1921.

Serial N0. 304,642.

and T as shown in Figs. 3 and 4:. The surfaces 4 and 6 are in effect breaking-clown surfaces as will appear later on. The lower .die is also formed with a half-round forginggroove 8 the forward end of which inter sects a concentric half-round forging-recess 9 of larger diameter, while the rear end of the groove 8 is enlarged to form a clearancethroat 10. The upper die is formed with a half-round forging-groove 11, a concentric half-round forging-recess 12 and a throat 13 to correspond respectively to the groove 8, recess 9 and throat 10 of the lower die. The rlght hand end of the lower die is formed with a forging-bevel 14s the forward edge of which terminates in a transverse forming-shoulder 15 centrally intersected by a half-round clearance-groove 16 leading into it from the front edge of the die. The rear edge of the forging-bevel 14 merges into a narrow, upwardly inclined transverse tipping-bevel 17 which in turn merges into an upstanding cutting-edge or hardy? 18 formed in part by beveling the rearedge of the die as at 19. The upper die is formed with a forging bevel. 20 corresponding in inclination to the bevel 1st and co-acting therewith. The upper die is also formed with a half-round clearancegroove 21 corresponding to the clearance-groove 16 of the lower die.

The lower die is additionally formed with a wedge-shaped positioning-recess 22 somewhat wider in pitch than thesquare tapered shank 23 of the tool to be produced, and designed to accurately position the said shank between the upper and lower dies preparatory to the stamping action of a numbering die 24 having beveled edges and located in an undercut slot 25 leading out of the bottom of a clearance groove 26 extending from the forward to the rear edge of the upper die. Under thisconstruction the numbering die 24: maybe moved forward or rearward as required, as well as interchanged with other dies having diiferent numbers.

In using my improved dies, a blank like, or substantially like, the blank 27 of Fig. 7, is subjected to the action of the flat forging-surfaces a and 6 which produces the square stem 28, the flaring outer end of which is'due to the inclined surfaces 5 and shank 23 of the finished tool.

It will be understood, of course, that in producing the square stem 28, the blank 27 is constantly rotated in quarter turns by the operator, who times the turning of the blank to the speed of the trip-hammer. The blank, partly developed, as shown in Fig. 8, is now subjected to the action of the half-round forging-grooves 8 and 11, whereby the round stem 29 is produced between the remaining unforged portion of the blank and the flaring end of the square stem 28 thereof, as shown in Fig. 9. During the opera-' tion of forging the round stem 29, the forging recesses 9 and 13 by receiving the forward end of the unforged portion of the blank, serve to keep the same centered with respect to the forging-grooves 8 and 11 so that the axis of the rounded stem 29 will coincide with the axis of the unforged' porti'on of the blank. The action of theconcentric forging-recesses 9 and 10 upon the blank, will be to upset the edges thereof as at 30. In other words, the function of the recesses 9 and 10 is to keep the blank centered during the forging of its round stem 29. It will also be understood that the blank is constantly rotated by the operator during the phase of the forging operation, just described.

The blank developed as in Fig. 9, is now subjected to the action of the beveled forging-surfaces i l and 20, whereby the square tapered shank 23' is formedv at the outer end of the round stem 29, the shoulder 31 between the tapered shank 23 and the round stem 29 being produced by the transverse formingshoulder 15 at the forward end of the forging bevel 14. The tipping bevel 17 forms the symmetrical tip 32 at the end of the square tapered shank After the conclusion of the forging oper. tion, the shank 23 is inserted into the positioning-recess 22 as far as it will go for its subjection to the action of the numbering die 24:.

lVith the dies heretofore used, the positioning of the blank between the dies has been a matter of eye-measurement and hand manipulation. The combination of these variable factors has resulted in an irregular product, since oftentimes the operator will manipulate the blank so as to produce a square tapered shank either too long or too short, very slight differences in. the initial placing of the blank between the dies resulting in considerable variations in'the length and size of the squaretapered shank produced. With my improved dies, on the con- V :trary, it does not devolve upon the operator to initially position the blankexactly, since the-length over all of the forging-bevel l4 corresponds to thelength of the square tapered shank 23 to, be produced,thecuttingedge 18 on the one hand, and the formingshoulder 15 on the other hand, estabhs hing the length of the square tapered shank and edge.

the cutting-edge immediately cutting off any excess of metal in case the blank was initially positioned too far rearward between the dies. Of course if the operator fails to initially place the blank sufficiently far rearward in the dies, he will secure an imperfect bit-shank owing to insufiicient stock. he should err, therefore, on the side of an excess of metal and will then secure perfect tapered bit-shanks in every instance at the trifling expense of the stock represented by the metal cut off by the cutting-edge 18. Wha-t I wish to emphasize is, that the -110- tion of the forging-bevels l4 and 20 and the forming-shoulder 15 and the cutting-edge 18 result in the production of a perfectly symmetrical square tapered shank. By making the groove 22 of slightly greater pitch than the taper of the bit-shank 23, the same is readily positioned in the die so that the shanks will be uniformly stamped. The stamp 24 may be positioned as required in the groove 22 and replaced or exchanged at will.

I do not limit myself to upper and lower dies constructed as shown and described, nor to following the forging sequence set forth, my improved dies being mainly characterized by their adaptation to produce square tapered shanks of uniform shape and size itsformingshoulder 15 and its cutting-edge 18 corresponding to the length of the square tapered shank to be produced. By preference the die will include the tipping bevel 17 adjacent to its cutting-edge 18, though this is not essential.

I claim 1. A lower die for forging the square tapered shanks of bit-stock tools, the said die having a forging-bevel corresponding in length to the length of the square tapered shanks to be forged, and flanked at its for: ward end by a transverse forming-shoulder and at its rear end by a transverse cutting- 2. A lower die for forging the square tapered shanks of bit-stock tools, the said die having a forging-bevel corresponding in length to the length of the square tapered fshanks to be forged, and flanked at its forward end by a transverse formin -shoulder at its rear end by a transverse cuttingedge and having a transverse t1pp1ngbevel located within its said cutting-edge.

3, A lower die forforging the square tapered shanks and round stems of bit-stock tools, the said die: having ahalf-round forging groove, the front end of which is intersected by a concentric half-round forging recess for the reception of the end of the bodyportion of the blank.

l. A lower die for forging the square tapered shanks and round stems of bit-stock tools, the said die having a tapered positioning-recess for receiving and holding the square tapered shanks for stamping the same.

5. An upper and lower die for forging the square tapered shanks of bit-stock tools, the said upper die having a clearance-groove in the bottom of which a removable, adjustable numbering-die is located, and the said lower die having a wedge-shaped positioning-recess arranged to register with the said clearance-groove of the upper die, and adapted to receive and position the square tapered shanks while being stamped by the said numbering-die.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

ELMER T. MGPHERSON.

Vitnesses J. HAnoLD FLYNN, C. L. WEED. 

